Video is the most powerful advertising medium, bar none, because it is the medium that most closely resembles real life. It combines sight, sound and motion and can help brands create personality, emotion or excitement. If a picture paints a thousand words, then a video paints a million.

Before Channel 4 launched in 1982, advertisers could only use the power of video advertising on one TV channel which was ITV or in the cinema. Today, there are literally hundreds of TV channels but even they are dwarfed by the plethora of choice that the internet offers. A lot has changed in 19 years!

The internet of course enables broadcast companies to deliver their TV shows via a different platform, and catch-up TV is growing more popular but the majority of video being viewed on the internet is short-form (3-5 minute clips) rather than long-form.

YouTube is obviously the largest video site, and the BBC iPlayer is also huge but there is also a huge amount of viewership of professionally produced video on almost every major publisher site from newspaper sites, to football clubs, fashion portals to parenting advice.

Video content is everywhere online, and you can be sure that wherever there are engaged eyeballs, the advertising pound won’t be far behind.

In 2009, the video advertising market was worth around 30m.

The IAB and PwC have recently released figures that show H1 2010 is already up to over 20m, and with the expected uplift in spend for Q4, some are predicting that the video market could have doubled to be as much as £60 by December 2010.

Most advertising, whether it be newspaper ads, online display advertising, outdoor advertising or even TV advertising works by pacing advertising around the content that is commanding the users eyeballs.

A video pre-roll sits in front of the content, and plays where the users main focus is.

Also, many advertising medium are shared experiences, and advertising occurs while the user is also focussing on something else. Watching video online is not usually done while doing something else, so the user’s attention is 100% focussed on the screen.

The industry standard way to measure the success of video advertising has yet to be born, but it is clear that judging success on the click through rate is the wrong way.

99% of video ads are TV ads, and they don’t have a call to action. If they don’t ask a user to click, then how can they be measured on a click through rate? Also, I believe it is counter-intuitive to expect a consumer to click on a video because they are interested in watching it, and then click on a pre-roll to take them away from that content before they have even watched the content.

Video viewership and advertising is predicted to continue its stellar growth into 2011 and beyond. As more publishers make more professional content and more advertisers increase their investment in online video advertising, the future looks bright.

Video content is already available on mobile devices, but I believe that as the network speeds increase, and the UI becomes as good over the mobile network as it is today over a wireless network, then viewership and advertising will start to explode.

The speakers including Bruce Daisley from YouTube, Ed Couchman from Channel 4, Rob Black, Chair of the IAB Video Council and Eyewonder, Camilla Day at PHD, Nicky Clarke from Sky, and me from the Telegraph.